PCIII Closed Throttle Values
So, yesterday, I hooked up the computer to the bike and PCIII. The closed throttle position was set at 3% instead of 0. So, I warmed up the bike for a few minutes, and when the idle slowed down, I reset the closed throttle position. Well, it continued to struggle idling and would spit and sputter, then die.
My questions are:
1. What rpm's should typical idle be?
2. What is a typical closed value position on the PCIII?
3. Is there another way to control how long the idle stays at a higher rpm?
4. What other things should I be looking for?
Attached are my recent values.
Last edited by mja52403; Oct 18, 2009 at 10:04 PM.
True duals
A/C kit
SS510G - cams
PCIII
Dyno
If it does the trick you could then write those numbers into your map. Remember that when you bump the numbers up using the buttons on the PCIII you increase all the cells throughout the RPM range the same amount. You maybe only want them in the 'zero' TP. This ought to solve the crappy running at idle. Messing with the zero throttle position isn't the way to fix this IMO.
1)I believe the idle is somewhere around 1000 rpm.
2)The closed position is supposed to be at 0. You're setting it so the PCIII knows the point at which you throttle 'sits' at zero.
3)IMO, the way to set idle properly is to add enough fuel at zero TP to make the bike idle nicely. (warm) I'd think the bike will take care of things when cold after the idle is set right warmed up.
4) I'd think your bike looks to run pretty lean at your settings. Just my opinion. I'd watch for signs of overheating. What are your timing numbers?
CN
Last edited by Comfortably Numb; Oct 20, 2009 at 02:50 AM.
What's your 0% throttle position numbers at 500 rpm, 1000rpm, and 1500rpm? Unless they're pretty high, increase 'em by 5 or so. Do it at 2% as well. If it solves the problem, great..If it makes it worse, go in the opposite direction, and take 5 off your baseline numbers.
Sounds to me like you're running a tad lean however, so increasing fuel should solve it. Sure it's possible that you could be running too fat instead, but either way you'll know which when you make your changes.
BTW..don't worry if you don't have 500rpm cells, and don't worry if you do, but are concerned about changing it because your bike doesn't idle that low. It'll bleed into the next cell, and we wanna affect your idle mixture even if you drop under 1000rpm.
I personally like 1200rpm on street bikes, but you have no external idle adjustment capability on EFI HD's.
Been watching the posts here, I have not had experiance with the PCIII so what I am stating here may not be of any usefulness. Could you be chasing your tail here? On the Magneti Marelli idle control, unlike the later Delphi style, the idle control physically moves the throttle plates and TPS values as it adjusts idle speed. If, for example due to an improper mixure, the idle control moves the plates further open as it trys to compensate for the proper idle RPM, the throttle position % would now be higher then when it was previously set to 0%. Let's say it is now 5% but if you reset it to 0%, then correct the mixture problem, the idle control will re-compenstate to a new throttle position value and the tune will be off again. Using this senario, maybe the throttle % should have been left at its 3%, then start tuning, it may have returned to its previously set 0% after proper low % fuel values programmed into the PCIII. Furthermore, possibly on an MM system, careful consideration would have to be given to the full range of the idle control on a PCIII for the full cold/hot throttle position % range of the idle control system.
Last edited by geargrinder; Oct 21, 2009 at 01:04 PM.
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On Tuesday, I was able to update the firmware and reload the map from Dynojet for my setup. I tweaked the map slightly based on Comfortably Numb's suggestions. I also reset the closed throttle position.
So, today was testing day as it has finally stopped raining. The biked started up nicely and I quickly noticed that moving from a stop was no longer a struggle like it was before when the bike was rather sluggish in first gear. The ride was great and the performance was just what I hoped for.
My ride took me 35 miles north along the Mississippi River on the Minnesota side, then back south along the river on the Wisconsin side. Fall colors aren't quite as good as past years, but that's ok, still great time to ride.
So, thanks to everyone who chimed in on my thread and special thanks to HDF for creating and managing such a great forum.




